The GRECC located at this hospital represents the leading edge of clinical care focusing on the needs of the aging veteran. We will recruit all 100 patients currently hospitalized at the Dementia Unit. We will also recruit from the outpatient memory clinic. We will enroll 400 AD patients total. Since, cases and controls will be ascertained from the same population, we also expect the socioeconomic status of individuals in these two groups to be the same. In the past year 9600 patients were treated on an outpatient basis. They were almost entirely white and male (>90%). The age demographics are 23% between 60-69, 23% between 70-79 and 5 % 80 or greater. The outpatients are seen for a wide variety of conditions. We plan to enroll 100 patients a year for 4 years (400 total). They will be seen once and have the same neuropsychological exams as the AD patients. Control subjects will be enrolled if their Mini-Mental score is greater than 24.